Non standard extensions for generated source files.

[sparhawk]

I have created some extensions like "*.ui" and "*.moc" to compile the special files from Qt. What I don't really understand though is, why, when I add such files to the project, I have to give it a "weight" to force that the compilation is done before the normal cpp files.
There are some files, not only these, but others like "yacc" etc, which create compilable output steps. And in the editor for setting up my own extensions, I have to define what output files. So if CB would calculate the dependency tree, it should know when a certain file has to be compiled, because of it's dependencies. I find it a bit strange that instread of using that information, I have to provide a weight to make it compile before the generated output files.